Composition of extraction-chromatographic material for selective extraction of mo-99 from irradiated uranium fuel

FIELD: chemistry.

SUBSTANCE: composition contains a compound of formula (I)

as a complexing component, where R is a C1-C12 alkyl, in percentage content of 1-99%, and the rest of the polymer matrix is a macroporous spherical granular copolymer of styrene with divinyl benzene LPS-500 with granule size of 40-200 mcm.

EFFECT: high sorption capacity with respect to Mo-99.

2 dwg

 

The invention relates to the field of chemical technology of production of radioactive isotopes for medical purposes. Mo-99 is of interest as a precursor of the radioisotope Tc-99, which is widely used in the global health system for the diagnosis and treatment of several diseases.

Currently, the main source of Mo-99 is irradiated uranium fuel. The high radioactivity of the solutions obtained by processing, puts forward a number of specific requirements to the methods of selective extraction of their contained components. To the greatest extent this can be achieved by a method of extraction chromatography using sorption materials (sorbents) of various types. Known sorbents do not always possess the necessary characteristics, so the development of new and highly efficient extraction-chromatographic sorption materials is of great interest.

The invention relates to compositions of sorption materials obtained by applying (impregnation) selective complexing compounds in organic and inorganic matrix.

The aim of the invention is to increase the selectivity of the selection of Mo-99 from nitric acid solutions obtained by dissolving the irradiated uranium fuel in nitric acid is the same. In addition to Mo-99 these solutions contain technetium, thorium, uranium, neptunium, plutonium and some shrapnel elements.

The closest analogues of the properties to the proposed technical solution is sorbents brand "Tarmacced" - spherical inorganic granular materials on the basis of hydrated oxides of zirconium, titanium and tin. For example, the described example of the use of these sorbents for separation of Mo-99 from sulfuric acid media [N.D. Batenkov, H., Denisov, T.A. NeoBux, L.M. Sharygin. The 99mTc generator based on inorganic sorbents brand "Tarmacced" U.S. Patent No. 6337055 from 08.02.2002.] The disadvantages of this example of the use of sorbents brand "Tarmacced" is the use of sulfuric acid solutions of uranium, because of corrosion problems imposes significant restrictions on the use of this method of radiochemical production of stainless steel equipment.

The closest in technical essence to the claimed technical solution is an example of using sorbent mark "Tarmacced T-5" to highlight the Mo-99 from nitric acid media [S.I. Smooth, M.V. Logunov, Y.A. Voroshilov, N.D. Batenkov, H., Denisov, L. Sharygin, C.V. Bugrov, V.B. have been Nikipelov, a method of obtaining a concentrate of the radionuclide 99mo RF Patent 2288516 from 25.04.2005]. This example is chosen as a prototype. Lack of use is isawanya of this sorbent for separation of Mo-99 is the solubility of the sorbent Tarmacced T-5 in dilute nitric acid, the need for correction of the composition of the initial solution and the low selectivity of the selection of Mo-99 in the presence of technetium, thorium, uranium, neptunium, plutonium, and some fission elements, the result is not always possible to obtain a concentrate of Mo-99 is required.

The task of improving the selectivity of the selection of Mo-99 from nitric acid solutions is solved in that the proposed composition of the new extraction chromatographic material impregnated type for selective extraction chromatographic extraction of Mo-99 from irradiated uranium fuel, including as a complexing component, the compounds of formula (I), where R represents alkyl, C1-C12with the percentage from 1 to 99% and the rest is a polymer matrix - macroporous spherical granular copolymer of styrene with divinylbenzene brand LPS-500 with a granule size of 40-200 microns.

Comparative analysis of the prototype allows us to conclude that the claimed technical solution for the selective extraction of Mo-99 is used sorption material of the other type, including as a complexing component connection I and macroporous Staropromyslovsky copolymer of styrene with divinylbenzene brand LPS-500, not Staropromyslovsky material based on hydrated OK the Idov zirconium, titanium and tin).

Synthesis of 1,5-Bis[2-(acetoxymethyl)-4-(ethyl)phenoxy-3-oxapentane, the structure of which is described by the formula I when R=Et carried out by us earlier [RF Patent №2391349 for the invention of the Russian Federation 1,5-Bis[2-(acetoxymethyl)-4-(ethyl)phenoxy-3-oxapentane as a ligand for selective extraction of Thorium(IV) in a series of Uranium(VI) and Lanthanum(III) from nitric acid media / Tsivadze, A., Baulin V., Baulin D.V., Tananaev I.G., Safiulin A.M. Appl. 03.12.2008 published 10.06.2010 (B. I. No. 16)]

The following examples illustrate the invention.

The method for producing the inventive extraction-chromatographic material.

The solution obtained by dissolving 3.0 g of 1,5-Bis[2-(acetoxymethyl)-4-(ethyl)phenoxy-3-oxapentane 45 ml of chloroform is rapidly added to a suspension containing 7.0 g of a copolymer of styrene with divinylbenzene brand LPS-500 size spherical granules 100-150 μm and 50 ml of chloroform. The resulting mixture was stirred on a magnetic stirrer for 1 h, then transferred to a round bottom flask and remove the solvent in vacuo on a rotary evaporator. The residue is transferred into a porcelain Cup and dried to constant weight at room temperature. The sorbent yield 10.0 g (100%).

Sorption characteristics of the proposed sorbent with respect to Mo-99 and a number of related elements (Th(IV)U(VI), Np(IV) and Pu(IV) was investigated by the method of frontal extraction chromatogra the AI at various concentrations of HNO 3. To determine the dynamic distribution coefficients of the analyzed elements of the front output curves were processed according to the method described in [brown t, Garcini, Extraction chromatography. M: Peace.: - 1978. 615 S.]. Dynamic distribution coefficients (Dw) extracted elements of the curve was calculated by the formula:

D=V0,5C0me

Where: V0.5- weight of the solution passing through the sorbent to half overshoot, g;

meis the mass of sorbent in the column,

The obtained values of the dynamic distribution coefficients for Mo(VI), Th(IV)U(VI), Np(IV), Pu(IV) to declare the sorbent is presented in graphical form according to Dw on the concentration of nitric acid 1 - Mo(VI), 2 - Th(IV), 3 - U(VI), 4 - Np(IV), 5 - Pu(IV). The composition of the sorbent: 15.5% of compound I; mass of sorbent 300 mg; the amount of sorbent granules 150-200 microns; mass concentration of elements: 20-80 mg/l (figure 1).

Based on these data we can conclude that differences in the values of the dynamic coefficients of Mo(VI), Th(IV)U(VI), Np(IV), Pu(IV) in the range of concentrations of nitric acid 3.5-6.0 allow practical separation of molybdenum from the companion elements of the inventive sorbent.

the alignment of the sorption ability of the proposed sorbent with the prototype (sorbent mark "Tarmacced-T-5" was carried out on the basis of the front output curves for Mo(VI). Dependence 1 received 600 mg of sorbent Tarmacced T-5"; the size of sorbent granules 150-200 microns; the dependence of 2 for 580 mg of the inventive sorbent containing 33% of compound I; the size of sorbent granules 150-200 microns. In both cases, the diameter of the chromatographic column was 4.6 mm; flow rate - 1 ml/min; the composition of the solution is 50 mg/l Mo 1 M nitric acid (figure 2).

In the above formula have been calculated values of Dwfor the proposed sorbent and prototype, the value of which amounted to $ 58.62 and 26.66 respectively. Therefore, the magnitude of the dynamic allocation ratio of molybdenum inventive sorbent is more than two times that of the sorbent mark "Tarmacced T-5".

The composition of the extraction chromatographic material impregnated type for selective extraction chromatographic extraction of Mo-99 from irradiated uranium fuel, including as a complexing component, the compounds of formula (I), where R represents alkyl, C1-C12in percentage from 1 to 99%, and the rest is a polymer matrix - macroporous spherical granular copolymer of styrene with divinylbenzene brand LPS-500, with a granule size of 40-200 μm



 

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